Syntheses, spectroscopic properties, and CU(I) complexes of all possible symmetric BI-1,10-phenanthrolines

Article abstract of DOI:10.3987/COM-04-10273

All possible symmetric bi-1,10-phenanthrolines (biphens) were synthesized by Ni-catalyzed coupling of corresponding halo-1,10-phenanthrolines. Their absorption and emission spectra were compared with those of phenanthroline as the reference compound. The spectral feature is explained by the molecular conformation, namely, coplanar 2,2′- and 3,3′-biphens and nearly bisected 4,4′- and 5,5′-biphens. The effects of additives, H⁺ or Zn²⁺, on the electronic spectra varied depending on the biphen ligand. The 2,2′-ligand formed a helical complex with Cu⁺ ions in a 2:2 ratio as revealed by spectroscopic titration and X-Ray analysis.

Full text of DOI:10.3987/COM-04-10273

HETEROCYCLES, Vol. 65, No. 3, 2005
551
HETEROCYCLES, Vol. 65, No. 3, 2005, pp. 551 - 562
Received, 4th November, 2004, Accepted, 11th January, 2005, Published online, 14th January, 2005
SYNTHESES,
COMPLEXES
SPECTROSCOPIC
PROPERTIES,
AND
CU(I)
OF ALL POSSIBLE
SYMMETRIC
BI-1,10-
PHENANTHROLINES
Shinji Toyota,* Akito Goto, Keiko Kaneko, and Takumi Umetani
Department of Chemistry, Faculty of Science, Okayama University of Science,
1-1 Ridaicho, Okayama, 700-0005, Japan. E-mail: stoyo@chem.ous.ac.jp
Abstract – All possible symmetric bi-1,10-phenanthrolines (biphens) were
synthesized by Ni-catalyzed coupling of corresponding halo-1,10-
phenanthrolines. Their absorption and emission spectra were compared with
those of phenanthroline as the reference compound. The spectral feature is
explained by the molecular conformation, namely, coplanar 2,2'- and 3,3'-biphens
and nearly bisected 4,4'- and 5,5'-biphens. The effects of additives, H+ or Zn2+, on
the electronic spectra varied depending on the biphen ligand. The 2,2'-ligand
formed a helical complex with Cu+ ions in a 2:2 ratio as revealed by
spectroscopic titration and X-Ray analysis.
INTRODUCTION
Multitopic ligands consisting of N-heterocyclic units have been widely used for the construction of
molecular architecture by self-assembly via coordination with metal ions.1,2 For example, oligomers of
2,2'-bipyridine and 2,2':6',2"-terpyridine subunits are useful components of molecular grids,3 ladders,4 and
helicates,5 owing to their rigid structures. There are also a number of applications of 1,10-phenanthroline
(phen) based multitopic ligands in supramolecular chemistry5a,6 as highlighted by the knot synthesis.7 In
most cases, however, phen moieties are separated by suitable chains or spacers, and the directly
assembled oligomeric structures are less popular because of synthetic limitations. Bi-1,10-
phenanthrolines (biphens) (1–4) are the simplest analogues of such oligomeric ligands. After the first
synthesis by Case in 1964 of 2,2'-biphen (1) and 5,5'-biphen (4) by Ullmann coupling or Skraup reaction,8
few studies of this type of ligands followed.9 It was only recently that the practical syntheses of 2,2'-
biphen (1) and 3,3'-biphen (2) by Ni-catalyzed coupling were again reported, and the synthetic access has
made it possible to study the complexation and other properties in detail.10–13 Furthermore, these

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HETEROCYCLES, Vol. 65, No. 3, 2005
heteroaryls (extended π systems) are attracting attentions as building blocks of potentially useful
electroluminescence14 and conducting materials.15 Therefore, we synthesized all possible symmetric
biphens including known compounds as basic ditopic ligands, and examined their interactions with acid
or metal ions (Zn2+ and Cu+) by spectroscopic methods.
6
5
4
7
8
3
N
N
N
10
N
2
3
1'
10'
9
9'
1
2'
N
N
3'
N
N
N
3'
8'
4'
7'
5'
6'
1
2
N
N
N
4'
5'
5
4
N
N
N
N
N
N
3
4
5
RESULTS AND DISCUSSION
Synthesis
Compounds (1) and (2) were prepared by the Ni-catalyzed coupling16 of 2-Cl-phen and 3-Br-phen,
respectively, according to the literature.10,11 4,4'-Biphen (3) was similarly synthesized from 4-Cl-phen in
66% yield: this new compound was satisfactorily characterized based on analytical and spectroscopic data.
As for 5,5'-biphen (4), it was reported that the Ni- or Cu-catalyzed reactions of the corresponding chloride
or bromide afforded none of the desired coupling product.8 However, we successfully obtained (4) from
5-Cl-phen using the same procedure as that applied to the other isomers.
Structure and conformational analysis
The molecular structures of biphen ligands (1–4) were calculated using the PM3 method. The energy
minimum structures are shown in Figure 1. Compound (1) preferred to take a planar conformation where
N1 and N1' were anti along the C2–C2' axis. This result was almost consistent with the X-Ray data
(dihedral angle: 10.0°).10 As the torsion angle of N1–C2–C2'–N1' was changed from 180° to 0°, the
energy was increased monotonically: the anti coplanar form was the only energy minimum among the
possible conformations. For 2, two coplanar conformations were obtained as the optimized structures,
where the anti form was slightly more stable than the syn form (energy difference ca. 1 kJ/mol). The
rotational barrier was only 5 kJ/mol via the nearly bisected conformation as the transition state. In
contrast, the two phen moieties were nearly bisected in the optimized structures of 3 and 4, the dihedral

HETEROCYCLES, Vol. 65, No. 3, 2005
553
angles being 90.2° and 92.6°, respectively. The coplanar conformations were considerably unstable
because of the steric interactions between the aromatic protons around the C–C axis. Although the
estimation of the rotational barriers of 3 and 4 by calculation was unsuccessful, we considered that their
barriers were as high as that in 1,1'-binaphthyl (94 kJ/mol),17 which could be regarded as a steric model.
92.5
180.0
92.6
1
3
4
180.0
0.0
anti-2
syn-2
Figure 1. Optimized structures of 1–4 by PM3 method. Values indicate dihedral angles between two
phen moieties.
1
Table 1. H NMR chemical shifts and multiplicity of biphens (1–4) and phen (5) ligands, and the Cu(I)
complex of 1. a
Compd
2,2'-H
—
3,3'-H
9.46 d
4,4'-H
8.50 d
5,5'-H
7.92 d
6,6'-H
7.85 d
7,7'-H
8,8'-H
9,9'-H
1
8.31 dd
8.28 dd
8.32 dd
8.26 dd
8.33 dd
8.27 dd
7.69 dd
7.54 dd
7.70 dd
7.70 dd
7.75 dd
7.65 dd
9.29 dd
8.18 dd
9.26 dd
9.29 dd
9.31 dd
9.21 dd
12⋅Cu+
—
8.33, 8.34 ABb
7.65, 7.71 ABb
2
2
3
4
5
9.60 d
9.38 d
9.24 dd
9.21 dd
—
8.65 d
—
7.99 d
7.92 d
7.67 d
7.96 s
7.81 s
7.69 d
7.49 dd
7.65 dd
7.34 d
—
7.78 dd
8.27 dd
7.81 s
aThe signals were assigned by the decoupling and NOE experiments. Multiplicity, s: singlet, d: doublet,
dd: double doublet, AB: AB quartet. bNot fully assigned.
The above structural features were reflected by the 1H NMR chemical shifts listed in Table 1. The proton
signal due to the 3,3'-H protons in 1 (d 9.46) was shifted downfield by ca. 2 ppm relative to the
corresponding signal in free phen (5) (d 7.65). The downfield shift was attributed to the ring current effect
of the attached aromatic rings as well as to the neighboring effect of the nitrogen atoms in the anti

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HETEROCYCLES, Vol. 65, No. 3, 2005
coplanar conformation. In contrast, the 5,5'-H signal in 3 (d 7.34) and the 4,4'-H signal in 4 (d 7.78) were
shifted upfield relative to the reference. These protons were found in the shielding region of the attached
aromatic rings in the bisected conformation.
UV and fluorescence spectra
The absorption and emission spectra of this series of biphens were measured in acetonitrile. The emission
spectra were recorded upon excitation at 305 nm. The absorption spectra of 1–5 are shown in Figure 2.
These data are compiled in Table 2.
6.0
6.0
4.0
2.0
0
4
(a)
(b)
4.0
2.0
0
1
e
e
3
2
5
5
200
300
400
200
300
400
l (nm)
l (nm)
Figure 2. Absorption spectra of 1–5 in MeCN.
Table 2. Absorption (lmax) and emission (lem) wavelengths and fluorescence quantum yield (Ff) of free,
protonated and metallated biphen (1–4) and phen (5) ligands measured in acetonitrile. a
+ H+
+ ZnCl2
(nm)
b
c
free
d
d
d
Compd
l
(nm)
l
(nm)
F
l
(nm)
l
(nm)
F
l
l
(nm)
F
f
max
em
f
max
em
f
max
em
1
354, 337,
321, 292
314, 273
390
0.22
346, 308, 247 434
0.14
380, 364,
304, 264
323, 281
414
0.030
2
3
366, 383 0.055
340, 289, 237 409
0.18
0.14
384
419
404
0.018
0.19
268, 232
384
378
0.039
0.061
280, 221
439
277, 229
275, 233
4
5
266, 231
263, 230
277, 224
303, 275,
272, 220
430
423
0.27
0.082
388，376 0.031
0.055
293, 272, 226 370, 387 0.050
b
c
aShoulder bands are not listed here. In the presence of excess methanesulfonic acid. In the presence of
excess ZnCl2. dQuantum yield was measured relative to a solution of quinine sulfate in sulfuric acid.

HETEROCYCLES, Vol. 65, No. 3, 2005
555
Compounds (3) and (4) afforded two intense absorption bands at ca. 230 and 265 nm due to π-π*
transitions (Figure 2(b)). This spectral pattern was quite similar to that of the parent phen ligand (5), and
indicated that the two phen groups approximately behaved as independent chromophores.18,19 This finding
was rationally explained by the nearly bisected conformation mentioned above. In contrast, the absorption
bands of 1 and 2 were broad and red-shifted compared with those of the other compounds, as have been
already pointed out in the literature.11 Preference for the coplanar conformations facilitated the electronic
interactions between the two phen moieties across the C–C axis.
The biphen ligands exhibited weak fluorescence with a maximum at around 380 nm, being slightly red-
shifted relative to that of phen. Whereas the fluorescence quantum yields of 2–5 were low (Ff < 0.06),
that of 1 (Ff 0.22) was significantly high compared with those of the other ligands. Therefore, the
coupling site is an important factor that contributes to the fluorescence efficiency in the biphen system.
Effect of acid and ZnCl2 on electronic spectra
The electronic properties of the phen derivatives were modulated by the addition of acid or metal ions to
form protonated or coordinated species. The UV and fluorescence spectra of 1–5 were recorded in the
presence of excess methanesulfonic acid or ZnCl2 (Table 2). There are several papers on the red-shifts of
the absorption and emission bands of phen derivatives by exogenous materials.19–21 Most of the biphen
ligands follow this general tendency although there are a few exceptional cases.
The influence of additives on the absorption bands was most remarkable in 1 among the biphen ligands
studied (Figure 3). The protonation changed the continuous bands in the range of 280–360 nm into a
broad peak centered at 308 nm without any red-shift. The metallation with Zn2+ ions increased the
intensities of the bands at 367 and 382 nm: this change was almost saturated when one equivalent of
ZnCl2 was added. As regards 2–4, the absorptions at the longest wavelength were red-shifted by both
additives. The degree of the red-shift was increased in the order of Zn2+ < H+ by the type of additive,
+MeSO3H
4.0
Free
2.0
e
+ZnCl2
0
200
300
400
l (nm)
Figure 3. Absorption spectra of 2,2'-biphen (1) without additive, and in the presence of excess MeSO3H
and ZnCl2 in MeCN.

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HETEROCYCLES, Vol. 65, No. 3, 2005
and 4 < 3 < 2 by the type of compound. The addition of H+ or Zn2+ influenced both the fluorescence
wavelength and intensity of each compound. The protonation of 1 resulted in a large red-shift of the
emission band (Stokes shift: ca. 80 nm) with a decrease in Ff. The fluorescence was considerably
quenched upon the addition of ZnCl2 for 1. A significant enhancement of the emission was observed for
2–4 by protonation, and only for 3 by metallation. These results contrasted those of 5 that showed only
weak emission under any conditions. These effects are attributed to not only the modification of a single
phen chromophore by the additives but also the structural change including conformation and
aggregation.
Complexation with Cu(I) ion
We prepared the Cu(I) complexes of 1–4 by treating the ligand with [Cu(CH3CN)4]PF6 in a 1:1 ratio in
acetonitrile. In all cases, the complexation occurred immediately with color change from colorless to dark
red. The Cu(I) complex of 1 was isolated as black crystals by concentrating the solution slowly. The
complexes of the other ligands could not be isolated as stoichiometrically or structurally defined forms.
The complexes of 3 and 4 decomposed upon standing for some time due to oxidation. On the other hand,
the complex of 2 was stable for a long time in solution, but gradually became gel-like while maintaining
the red color. These results indicated the formation of polymeric complexes, although we could not obtain
any information on the degree of polymerization by spectroscopic measurements.
1
The properties and structures of the complex of 1 were further explored. In the H NMR spectra, the
aromatic signals, particularly the 3,3'-H and 9,9'-H signals, were shielded compared with those of the free
ligand 1 (Table 1). This tendency is generally observed in the metal complexes of phen derivatives.9d An
ORTEP drawing of the Cu(I) complex of 1 is shown in Figure 4. The structure consists of two biphen
ligands and two tetrahedrally coordinated Cu ions that form a double helix along the metal centers.
Figure 4. ORTEP drawing of [Cu212](PF6)2. Counter anions are omitted for clarity. Four phen units are all
related to symmetric operations.

HETEROCYCLES, Vol. 65, No. 3, 2005
557
The copper atom is unequally coordinated to the two types of N atoms, Cu–N1 2.081(5) and Cu–N2
2.013(6) Å. The bond angles are significantly small for N1–Cu–N2 (81.8(3)°) and large for N2–Cu–N2"
(142.9(3)°) and N1–Cu–N1" (133.0(3)°) compared with 109.5°. This coordination mode is common to
the Cu(I) complexes of 2,2'-biphen derivatives, 9c,d and contrasts the 1:1 Ni(II) complex having a nearly
square planar geometry.10 The two phen moieties in each biphen ligand are twisted by 51° about the C2-
C2' bond from the syn conformation and the distance between the two Cu atoms is 3.360(2) Å; these
structural parameters are helpful in characterizing the helical geometry. The corresponding parameters are
31° and 2.92 Å for the Cu complex of 6,9d and 64° and 3.59 Å for that of 79c in the reported X-Ray
structures, which carry extra methylene chains across positions 3 and 3'. The helical pitch is increased in
the order of the complexes of 6, 1, and 7, reflecting the conformational mobility of the two phen moieties.
N
N
N
N
N
N
N
N
6
7
3.0
2.0
1.0
0
e
220
380
540
l (nm)
Figure 5. UV spectra of 2,2'-biphen (1) during titration with [Cu(MeCN)4]PF6 (0, 0.2, 0.4, 0.6, 0.8, 1.0,
and 2.0 eq) in MeCN:CH2Cl2 (1:1). Arrows indicate increase or decrease in intensity of each
peak.
The course of complexation of 1 with Cu+ was monitored by UV titration experiments. As the Cu+ reagent
was added to a solution of 1 in acetonitrile, the absorptions at 290–360 nm were decreased and broad and
weak bands appeared around 440 nm with a shoulder extending to 650 nm with some isosbestic points
(Figure 5). The new absorption bands were attributed to metal-to-ligand charge transfer, and were
typically observed around 450 nm for phen complexes. The spectrum remained unchanged when more

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HETEROCYCLES, Vol. 65, No. 3, 2005
than one equivalent of metal reagent was added. These observations strongly support the hypothesis that 1
exclusively forms a Cu+ complex in a 1:1 molar ratio under a simple equilibrium system. Although
ligands (2–4) exhibited spectral changes upon Cu+ addition accompanied by the appearance of new bands
at longer wavelengths, there were no clear isosbestic points during the titration. This result suggests that
several species exist in equilibrium even though Cu+ ions are sufficiently present in the solution. This
difference is related to the orientation of the two coordination sites in 2–4, which can form not a dinuclear
complex but a mixture of highly aggregated complexes because of the structural restriction.
In summary, all the symmetric bi-1,10-phenanthrolines were prepared by Ni-catalyzed coupling. Each
compound possesses characteristic absorption and emission spectra depending on the structural or
conformational circumstances, which are also modulated by acid or metal ions. These biphen ligands are
expected to widen the scope of metal complex design in the field of supramolecular or functional
molecular chemistry.
EXPERIMENTAL
1H and 13C NMR spectra were measured on a Gemini-300 at 300 and 75 MHz, respectively. HRMS were
measured on a JEOL JMS-700 MStation spectrometer. Elemental analyses were performed with a Perkin-
Elmer 2400-type analyzer. UV spectra were measured with a Hitachi U-3000 spectrophotometer with a
10 mm cell. Fluorescence spectra were measured with a JASCO FP-6500 spectrometer. Only selected
physical and spectroscopic data are described for 1 and 2. 5-Cl-phen was purchased from Aldrich
Chemical Co. 4-Cl-phen was prepared according to the method in the literature.22
5,5'-Bi-1,10-phenanthroline (4). A solution of NiCl2⋅6H2O (266 mg, 1.12 mmol) and PPh3 (977 mg, 3.72
mmol) in 10 mL of DMF was degassed by bubbling argon gas for 30 min. To the solution was added zinc
powder (72 mg, 1.10 mmol), and the mixture was stirred for 3 h under argon. After the addition of
tetraethylammonium iodide (240 mg, 0.935 mmol) and 5-Cl-phen (200 mg, 0.933 mmol), the whole
mixture was heated at 55 °C for 14 h. The reaction mixture was poured into a solution of ca. 1 g of KCN
in 30 mL of 10% aqueous ammonia, and stirred for 1 h at rt. The solid was collected by filtration and
washed with hexane to remove PPh3. The crude material was purified by chromatography on alumina
using chloroform/hexane 1:3–1:1 as eluent. Recrystallization from chloroform afforded 118 mg (71%) of
the pure product as pale yellow crystals. mp 367–369 °C (decomp, lit. 336–337 °C).8 1H NMR (300 MHz,
CDCl3) d (ppm): 7.49 (2H, dd, J = 4.3, 8.4 Hz), 7.75 (2H, dd, J = 4.4, 8.2 Hz), 7.78 (2H, dd, J = 1.7, 8.2
Hz), 7.96 (2H, s), 8.33 (2H, dd, J = 1.7, 8.1 Hz), 9.24 (2H, dd, J = 1.7, 4.2 Hz), 9.31 (2H, dd, J = 1.7, 4.4
13
Hz). C NMR (75 MHz, CDCl3) d (ppm): 123.2, 123.6, 128.0, 128.1, 128.6, 134.5, 135.3, 136.1, 146.1,
146.2, 150.5, 150.9; UV (MeCN) lmax (nm) (e): 231 (61500), 266 (46500), 298 (10600), 325 (1850, sh).

HETEROCYCLES, Vol. 65, No. 3, 2005
559
HRMS (FAB): calcd for C24H14N4: 359.1297 (MH+), found: 359.1335. Anal. Calcd for
C24H14N4⋅1/2(CHCl3): C, 70.38; H, 3.50; N, 13.40. Found: C, 70.06; H, 3.63; N, 13.53.
4,4'-Bi-1,10-phenanthroline (3). This compound was similarly prepared from 4-Cl-phen. The crude
product was purified by chromatography on silica gel (Si-NH) with chloroform/hexane 1:1 as eluent.
Recrystallization from chloroform afforded 66% of the desired compound as a white powder. mp
1
352–355 °C (decomp). H NMR (300 MHz, CDCl3) d (ppm): 7.34 (2H, d, J = 9.2 Hz), 7.67 (2H, d, J =
9.2 Hz), 7.69 (2H, d, J = 4.5 Hz), 7.70 (2H, dd, J = 4.4, 8.1 Hz), 8.26 (2H, dd, J = 1.8, 8.1 Hz), 9.29 (2H,
dd, J = 1.8, 4.4 Hz), 9.38 (2H, d, J = 4.5 Hz). 13C NMR (75 MHz, CDCl3) d (ppm): 123.4, 123.5, 123.7,
126.8, 127.2, 128.4, 135.9, 144.1, 146.1, 146.4, 149.7, 150.7. UV (MeCN) lmax (nm) (e): 232 (53200), 268
(43000), 280 (30400), 299 (12500), 328 (1770, sh). HRMS (FAB): calcd for C24H14N4: 359.1297 (MH+),
found: 359.1277. Anal. Calcd for C24H14N4⋅1/2(H2O): C, 78.46; H, 4.12; N, 15.25. Found: C, 78.82; H,
4.14; N, 15.41.
2,2'-Bi-1,10-phenanthroline (1). This compound was prepared from 2-Cl-phen in 71% yield. mp
364–366 °C (lit., 370 °C).8 1H NMR (300 MHz, CDCl) d (ppm): 7.69 (2H, dd, J = 4.4, 8.1 Hz), 7.85 and
3
7.92 (4H, ABq, J = 8.8 Hz), 8.31 (2H, dd, J = 1.7, 8.0 Hz), 8.50 (2H, d, J = 8.5 Hz), 9.29 (2H, dd, J = 1.7,
4.4 Hz), 9.46 (2H, d, J = 8.5 Hz). 13C NMR (75 MHz, CDCl3) d (ppm): 122.4, 122.9, 126.7, 126.9, 129.0,
129.2, 136.3, 137.0, 145.7, 146.5, 150.5, 156.2; UV (MeCN) lmax (nm) (e): 241 (48300), 260 (18300), 292
(28800), 321 (23200), 337 (20500), 354 (22000), 367 (4350, sh), 382 (1310, sh).
3,3'-Bi-1,10-phenanthroline (2). This compound was prepared from 3-Br-phen in 62% yield; mp
365–366 °C (lit. >300 °C).11 1H NMR (300 MHz, CDCl3) d (ppm): 7.70 (2H, dd, J = 8.0, 4.2 Hz), 7.92
and 7.99 (4H, ABq, J = 9.1 Hz), 8.32 (2H, dd, J = 1.6, 8.1 Hz), 8.65 (2H, d, J = 2.2 Hz), 9.26 (2H, dd, J =
13
1.4, 4.4 Hz), 9.60 (2H, d, J = 2.4 Hz). C NMR (75 MHz, CDCl3) d (ppm): 123.3, 126.6, 127.5, 128.6,
129.1, 132.6, 134.0, 136.0, 146.0, 146.3, 149.2, 150.7. UV (MeCN) lmax (nm) (e): 216 (15300), 221
(15300), 273 (32300), 314 (19300).
Measurement of electronic spectra. All measurements were carried out with a 10 mm cell in
spectroscopic grade solvents that were degassed before use. Sample was prepared by dissolving a ligand
in acetonitrile to make a concentration of ca. 5¥10–5 mol/L for UV measurement and 1–3¥10–6 mol/L for
fluorescence measurement. The spectra were first measured without an additive, and then with a large
excess of methanesulfonic acid (10 mL per 10 ml of sample solution) or 10 molar amount of ZnCl2. The
emission spectra were measured upon excitation at 305 nm, and the quantum yield was determined with
quinidine sulfate solution in 1.0 mol/L sulfuric acid as reference. For the titration experiment, each ligand
was dissolved in dichloromethane/acetonitrile (1:1) to make a concentration of 1.0¥10–4 mol/L because of
poor solubility in acetonitrile. The spectra were measured repeatedly after each addition of a certain
amount of [Cu(MeCN)4]PF6 solution in the same solvent.

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HETEROCYCLES, Vol. 65, No. 3, 2005
Preparation of Cu(I) complex. To 10 mL of degassed acetonitrile were added [Cu(MeCN)4]PF6 (50 mg,
0.14 mmol) and 2,2'-biphen (1) (53 mg, 0.14 mmol) under argon. The solution became dark red
immediately after the addition of the ligand. The solution was concentrated by slow evaporation to afford
64 mg (82%) of dark red crystals. mp > 300°C (decomp). 1H NMR (300 MHz, CDCl3) d (ppm): 7.54 (2H,
dd, J = 4.5, 7.9 Hz), 7.65 and 7.71 (4H, ABq, J = 9.0 Hz), 8.18 (2H, d, J = 4.5 Hz), 8.28 (2H, d, J = 7.9
Hz), 8.33 and 8.34 (4H, ABq, J = 8.3 Hz). UV (MeCN) lmax (nm) (e): 222 (41700), 261 (26900), 434
(3100), 555 (1400). Anal. Calcd for C48H28N8Cu2F12P2: C, 50.82; H, 2.49; N, 9.88. Found: C, 50.44; H,
2.39; N, 9.90. The other ligands were similarly treated with the Cu reagent to give red solutions from
which the complexes could not be isolated in pure form.
Crystal Data of Cu(I) complex of 1. The data were collected on a Rigaku RAXIS-IV diffractometer. All
intensity measurements were performed using graphite monochromated Mo-Ka radiation (l = 0.71073
Å). Single crystals of the Cu(I) complex of 1 were recrystallized from acetonitrile. Formula
C48H28N8Cu2F12P2, MW = 1133.82, orthorhombic, space group Fddd (no. 70), a = 29.18(1), b = 38.10(2),
c = 7.940(3) Å, V = 8826(6) Å3, T = 296 K, Z = 8, Dcalcd = 1.71 g/cm3, m = 11.35 cm–1, 2274 reflections
measured and used in all calculations. The final R1(F) = 0.054 , wR2(F2) = 0.176, GOF 1.00. CCDC
reference number 243741.
MO calculation. The PM3 calculations of 1–4 were performed using the MOPAC 2000 program on a
personal computer. The molecular models in Fig. 1 were generated by the Chem3D Pro program (ver.
5.0).
ACKNOWLEDGEMENTS
This work was partly supported by a special fund from the Japan Promotion and Mutual Aid Corporation
for Private Schools of Japan. The authors thank Mr. S. Hirano and Dr. N. Tanifuji for assistance of X-Ray
data analysis, and Messrs. R. Tanaka and K. Kato for technical assistance.
REFERENCES AND NOTES
1. J. -M. Lehn, 'Supramolecular Chemistry: Concepts and Perspective, ' VCH, Weinheim, 1995, Ch. 9.
2. 'Comprehensive Supramolecular Chemistry, ' ed. by J. L. Atwood, J. E. D. Davies, D. D. MacNicol,
and F. Vögtle, Elsevier, Oxford, 1996, Vol. 9.
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